A man who claimed allegiance to Isis (Islamic State) stabbed a French policeman to death yesterday before he was killed in a dramatic police operation, sources close to the investigation said.
A news agency linked to Isis said the attack had been carried out by an "Islamic State fighter".
French prosecutors have launched an anti-terror probe after the policeman and his partner were killed at their home in the Paris suburb of Magnanville.
Interior Minister Bernard Cazeneuve said it was a "terrorist act".
Witnesses told investigators the man may have shouted "Allahu akbar" (God is great) as he stabbed the policeman repeatedly outside his home before holing up inside with the woman and the couple's 3-year-old son. The partner was found dead but the child was rescued.
Loud detonations were heard at the scene as elite police moved in following failed negotiations with the attacker, who claimed allegiance to Isis while talking to officers, sources close to the inquiry told AFP.
"The anti-terror department of the Paris prosecution service is taking into account at this stage the mode of operation, the target and the comments made during negotiations," one source said.
Two French officials identified the killer as Larossi Abbala, a 25-year-old who had a past terrorism conviction for recruiting fighters for jihad in Pakistan.
The two officials said Abbala was from the western Paris suburb of Mantes-la-Jolie and was convicted in 2013 to three years in prison, including six months suspended for association with a terrorist enterprise.
The Site Intelligence Group, a US-based monitor, cited the Isis-linked Amaq News Agency as saying on its Telegram channels: "Islamic State fighter kills deputy chief of the police station in the city of Les Mureaux and his wife with blade weapons near #Paris."
The attack comes as France hosts the Euro 2016 football tournament under tight security - still reeling from jihadist attacks in Paris in November that left 130 people dead.
The slain policeman was said to be 42 years old and worked in nearby Les Mureaux.
His partner was a local police official.
President Francois Hollande said in a statement that he "strongly condemned this odious act".
"A police commander and his partner, a civil servant at the interior ministry, were shamefully murdered this evening," Hollande said.
"All light will be shed on the circumstances of this terrible tragedy," he added, announcing a meeting of top officials at the presidential palace early Tuesday.
Officers found the woman's body when they stormed the house, and the attacker was killed in the assault, the Interior Ministry said.
- AFP, AP